His Infinite Masquerade

Surveil 4. Then put a legendary spell from your
graveyard into your hand.
Cipher (Then you may exile this spell card encoded
on a creature you control. Whenever that creature
deals combat damage to a player, its controller may
cast a copy of the encoded card without paying its
mana cost.)
"His name is Lazav, planeswalker. If you want any
hope of surviving, you'll need to find him." -Lazav